Par to lux conversion - real world T5 numbers

[Scott.h]

I have sps high, mid and some 1" from the bottom and all are well. I just wanted to understand a little better about whats going in my box.
If there was some tweeking i could do i would consider it.

Im not an expert by no means. I can tell you I've had corals live in lower light then what the text book says. Before I had the par or lux meters I did what everyone does. Judge by sight. I've had acros in 100 par. (There are some lower light acros too) When I bought the par meter I was surprised at how low of light I really had. My frag tank had a 4 bulb aquatic life t5 fixture that only puts out 125 just under the surface. It looked bright and everything was ok. Too much light can be worse then low light too. Now with swaping this new tank over, all my LPS that were on the bottom of that frag tank are having a hard time adjusting to 75 par with the new fixture at 25%. Those are 150 par corals all day long. Even after 3 weeks, so I lower the light, wait for the polyps to extend out, and increase a few percent a week. I'm only doing that so I can have high light sps on the top rocks and lower light at the floor.

 

[Acro maniac]

Im not an expert by no means. I can tell you I've had corals live in lower light then what the text book says. Before I had the par or lux meters I did what everyone does. Judge by sight. I've had acros in 100 par. (There are some lower light acros too) When I bought the par meter I was surprised at how low of light I really had. My frag tank had a 4 bulb aquatic life t5 fixture that only puts out 125 just under the surface. It looked bright and everything was ok. Too much light can be worse then low light too. Now with swaping this new tank over, all my LPS that were on the bottom of that frag tank are having a hard time adjusting to 75 par with the new fixture at 25%. Those are 150 par corals all day long. Even after 3 weeks, so I lower the light, wait for the polyps to extend out, and increase a few percent a week. I'm only doing that so I can have high light sps on the top rocks and lower light at the floor.

Believe me i have seen first hand that corals csn live in well under there desired lighting. I have a friend that used led strip light just blue and white to grow lps and had nice growth and a good looking tank. When he suggested moving into sps i offered to put together some lights for him. He replied, I have plenty of light.
Yeah i dont think so but ok.
Well a month later when alll the new sps frags were brown and stning from the base. I offered again to put a fixture together and he agreed. But he would only let me do to strings of 14 leds. Alright whatever so i made 1 string rb and the other v, tv,hv,b,um . Which isnt much on a 6foot tank. It ended up being a strip 5 ft long. When plugged it in he , he said holly crap that way to bright im gonna fry everything in my tank. I reassured he that it wasnt very much light at all for that size tank. And to just run the blues 6 hours for now and the uv 1 hour. Then will see where your at in a week or so. This all while the old lights are on there normal schedule.
Day 3 seasons greetings cap bleached and orange cap bleached. If he would have told me earlier we could have caught it the first day when they should signs of bleaching and cut back yo half an hour uv.
He thought they were coloring up.
So know hes upset and tinks hes right that the lights are way to powerful and i explain to him that there really not its just you never really had any light over your tank and now you have some. Its just gonna take alittle time for things to adjust.
Anyway i told i have plenty more monti caps in the frag tank ill hook him up.
Thats what got me thinking if like to understand more about the lights we use and what is or isnt beneficial

 

[Scott.h]

Yeah, for some that have years of experience using specific lighting they have a good itea of what grows where under specific light fixtures. But until you get to that point light meters really take the guess work out of it. Recognizing the first signs of retraction or bleaching helps too.

 

[Acro maniac]

My tanks have been all led since 2009 prior to that it was hailid and t5.
My desire to understand more stems from wanting to know what the numbers are in my tanks. So im able to help other local reefers with location in their for the same corals to help with success rates. At the leadt ill know the lighting was sufficient

 

[Acro maniac]

Fwiw this the current reading in florida clear sky. (6 miles from ora greenhouse).
Should we be trying to duplicate this?

 

[saltyfilmfolks]

Fwiw this the current reading in florida clear sky. (6 miles from ora greenhouse).
Should we be trying to duplicate this?

that meter is not working correctly. 146,000 is more then the sun and sky.

 

[ksc]

Only off about 50%, common with these cheap lux meters.

 

[saltyfilmfolks]

thats a phone app.

 

[ksc]

thats a phone app.

I see that now. That says "Device Max Range 60,000 lux" so not a good app. for measuring the sunlight.

 

[Acro maniac]

that meter is not working correctly. 146,000 is more then the sun and sky.

Some people use those old hydrometers that are not calibrated but they recreate the same reading. Would it not be the same? Meaning the numbers could be way off but as long as your recreating the same reading its good? Or are you saying the variance is going to be be completely differant

 

[Acro maniac]

I see that now. That says "Device Max Range 60,000 lux" so not a good app. for measuring the sunlight.

I see that now. That says "Device Max Range 60,000 lux" so not a good app. for measuring the sunlight.

I gurss Ill be purchasing a meter thought i could get an idea with the phone app

 

[saltyfilmfolks]

Some people use those old hydrometers that are not calibrated but they recreate the same reading. Would it not be the same? Meaning the numbers could be way off but as long as hour recreating the same reading its good? Or are you daying the variance is going to be be completely differant

no the sun in the tropics at peak is 108,000 lux. Dark is zero. Thats how I knew.
A camera operates on reflected light, it hits an object bounces into the camera, when doing this at also reads brighter light directly(the sun is probably 146000 lux if you look directly at it.)
An incidental reading is what we want in determining intensity levels. Par meters and lux/fc all measure the amount of of light where they hit, this is the point of incidence.

edit some apps do use the light sensor not the camera. but the question is which one is that.

 

[Acro maniac]

no the sun in the tropics at peak is 108,000 lux. Dark is zero. Thats how I knew.
A camera operates on reflected light, it hits an object bounces into the camera, when doing this at also reads brighter light directly(the sun is probably 146000 lux if you look directly at it.)
An incidental reading is what we want in determining intensity levels. Par meters and lux/fc all measure the amount of of light where they hit, this is the point of incidence.

edit some apps do use the light sensor not the camera. but the question is which one is that.

So its not that far off then cause i was pointed directly at the sun and looking for the highest reading

 

[saltyfilmfolks]

So its not that far off then cause i was pointed directly at the sun and looking for the highest reading

if i point my incident meter directly at the sun I will never get 146000 lux. If you pointed par meter at the sun they way you suggest it would be 2700 PAR. thats impossible on this planet.
Incident and reflected metering.
In aquaria, we want incidence, the amount of light falling on the object.

 

[Acro maniac]

if i point my incident meter directly at the sun I will never get 146000 lux. If you pointed par meter at the sun they way you suggest it would be 2700 PAR. thats impossible on this planet.
Incident and reflected metering.
In aquaria, we want incidence, the amount of light falling on the object.

Understood now thanks

 

[saltyfilmfolks]

Understood now thanks

no sweat. all forms of testing can be pretty confusing

 

[Acro maniac]

if i point my incident meter directly at the sun I will never get 146000 lux. If you pointed par meter at the sun they way you suggest it would be 2700 PAR. thats impossible on this planet.
Incident and reflected metering.
In aquaria, we want incidence, the amount of light falling on the object.

So am i wasting my time with thiz phone app.

 

[saltyfilmfolks]

So am i wasting my time with thiz phone app.

yup.
Pretty sure I'm wasting my time with this red sea Mag kit. it cost a lot more than a lux meter.

 

[Acro maniac]

This is sun light as it falls currently in south florida is this a more accurate measurment

 

[saltyfilmfolks]

This is sun light as it falls currently in south florida is this a more accurate measurment

only if its really cloudy.